Electronically controlled camera shutter

ABSTRACT

An electronically controlled shutter comprises a braking mechanism for braking the movement of a sector opening member so as to open the shutter diaphragm sectors at a lower speed than when they are closed, a diaphragm setting member for manually setting the diaphragm aperture value and a photoreceptor for measuring the light reflected from the film surface so as to automatically control exposure by integrating the output of the photoreceptor. The shutter further includes a mechanism for selectively enabling or disabling the braking mechanism, whereby the shutter is adapted for both programming exposure and diaphragm preset exposure.

United States Patent Kobayashi [451 Sept'. l i, 1973 [54] ELECTRONICALLYCONTROLLED 3,353,462 11/1967 suzuki 95/10 CT CAMERA SHUTTER 3,348,46010/1967 Schmitt 95/10 CT [75] Inventor: Tatsuo Kobayashi, Osaka, JapanPrimary Examiner joseph F Peters, Jr. [73] Assignee: Minolta CameraKabushiki Kaisha, Attorney-Stanley Woldef Osaka, Japan [22] Filed; Dec.16, 1971 [57] ABSTRACT Appl. No.: 208,778

[52] U.S. Cl. 95/10 CE, 95/53 EB, 95/63, 95/64 B [51] Int. Cl. G03b7/08, G03b 9/24 [58] Field of Search 95/10 C, l0 CE, l0 CT, 95/10 CD, 53EB, 63, 64 B [56] References Cited UNITED STATES PATENTS 3,375,7694/1968 Kiper 95/63 3,638,544 2/1972 Kitai 95/10 CT 3,662,664 5/1972Goshima 95/63 An electronically controlled shutter comprises a brakingmechanism for braking the movement of a sector opening member so as toopen the shutter diaphragm sectors at a lower speed than when they areclosed, a diaphragm setting member for manually setting the diaphragmaperture value and a photoreceptor for measuring the light reflectedfrom the lm surface so as to automatically control exposure byintegrating'the output of the photoreceptor. The shutter furtherincludes a mechanism for selectively enabling or disabling the brakingmechanism, whereby the shutter is adapted for both programming exposureand diaphragm preset exposure.

19 Claims, 9 Drawing Figures PATENTE] SEP] l ISYS SHEET s ur 5 Fig.8

ELECTRONICALLY CONTROLLED CAMERA SHUTTER BACKGROUND OF THE INVENTION Thepresent invention relates to an electronic shutter the shutter speed ofwhich is automatically controlled by measuring the light reflected fromthe film surface, more particularly to improvements in an electronicshutter of the type wherein the diaphragm aperture is preset at asuitable value and the measurement of the reflected light is initiatedupon the sectors being initiated into an opening action so as to controlthe exposure time automatically.

The electronically controlled shutter of the diaphragm preset exposuretype heretofore used includes indicator means such as a lamp forindicating excessive brightness for which automatic exposure isunavailable so that if an improper diaphragm aperture value is set whena subject of a relatively high brightness is to be photographed, theindicator means emits a signal. Accordingly, the camera of this type istroublesome to handle in that when such signal is emitted, the diaphragmhas to be reset to provide a smaller diaphragm aperture.

Electronically controlled shutters for automatically controlling theshutter speed are of two systems: one being the so-called programmingexposure system wherein the shutter speed and the diaphragm aperture ofthe camera objective lens, factors which determine an exposure, are setwith predetermined combinations for automatic determination of exposureand the other being the diaphragm preset exposure system wherein thediaphragm aperture value of the lens is set beforehand by a manuallymovable member to automatically determine the exposure time.

Each of these two systems has advantages and disadvantages peculiarthereto. For example, the programming exposure system assures a veryeasy photographing operation and is therefore suitable for beginnersbecause the exposure is automatically controlled merely be depressingthe shutter button free of a troublesome adjustment of the diaphragmaperture, whereas it is not adapted for more sophisticated photographingskill in being incapable of varying exposure time or diaphragm aperturesince the combination of exposure time and diaphragm aperture value fora given subject is automatically determined. On the other hand, thediaphragm preset system has the aforementioned drawback because it isnecessary to previously determine the diaphragm aperture value of theobjective lens, which narrows the range in which the shutter is adaptedfor an automatic exposure.

These drawbacks will be eliminated by an electronically controlledshutter which is operable on both the programming exposure system anddiaphragm preset exposure system.

SUMMARY OF THE INVENTION cordance with the brightness of the subject,the sectors being adapted to be closed in response to the output of aphotocell which measures the reflected light from the film surfaceindicating the extent of opening of the sectors.

Another object of this invention is to provide an electronicallycontrolled shutter whereby photographs can be taken on the programmingexposure system wherein the exposure making operation is controlledfullyautomatically by merely depressing the shutter button to give aproper exposure to the film, the shutter further being adapted for aphotographing operation of the diaphragm preset exposure type of system.

In accordance with this system, a sector opening member for driving thesectors in the opening direction to expose the sensitive coating of thefilm is provided with braking means so as to permit the sectors to openmore slowly than when they are closed. The braking means exerts abraking action on the sector opening member during the period from theinitiation of sector opening action until the termination thereof.

A diaphragm setting member for manually setting the diaphragm aperturevalue is rotatably mounted, for instance, on the lens barrel of thecamera. Part of the diaphragm setting member or a member operativelyassociated therewith stops the movement of the sector opening member ata position where the sectors controlled thereby define the presetdiaphragm aperture.

A photoreceptor disposed within the camera body has a photocell forreceiving the light reflected from the film face when the sectors startto open, and the exposure of the sensitive coating on the film iscontrolled by an exposure time control electric circuit which integratesthe output of the photoreceptor to automatically determine and therebycontrol the exposure time.

Thus, the depression of the shutter button permits the sectors to startopening, whereupon the electric circuit starts to integrate the outputof the photoreceptor. While being braked during the opening action bythe braking means acting on the sector opening member, the sectorsprogressively open to give a diaphragm aperture of the preset value.While the sectors are open, the electric circuit continues to integratethe output of the photoreceptor until the integrated voltage reaches apredetermined value, whereupon the circuit actuates a sector closingmember to close the sectors. Accordingly, if a preset diaphragm aperturevalue is outside the range in which the shutter is automaticallyoperable for a given subject of a high brightness, the sectors closebefore they are opened to the diaphragm aperture setting to completeexposure immediately when it is detected that the sensitive coating ofthe film has been given a proper amount of exposure. If the presetdiaphragm aperture value is within the range of automatic exposureoperation for a highly bright subject, the sectors will of course operito the diaphragm aperture preset by the diaphragm setting member andclose upon the integrated voltage reaching the predetermined value. Y

v The braking means causes the sectors to move more slowly for openingaction than for closing action, assuring that the photocell willfunction to measure the light while the sectors are opened, whileensuring integration of the output from the photoreceptor by theexposure time control electric circuit.

In order to enable the camera to take photographs both on programmingexposure system and diaphragm preset exposure system, there is providedmeans for latching or unlatching the braking means for the sectoropening member by a diaphragm setting member or b some other member.

Thus when a photographis to be taken with the programming exposuresystem, the diaphragm setting member is manipulated to set the diaphragmat the value of maximum aperture of the objective lens or greater andthe sector opening member is braked by the braking means to make thesectors open at a lower speed than whenthey close.

Accordingly, until the sectors open'to the maximum diaphragm aperture orbefore they open to the maximum aperture, the electric circuit forcontrolling exposure time integrates the output of the light receivingportion to actuate the sector closing memberv and thereby close thesectors upon detecting that the integrated voltage has reached thepredetermined value.

If photographs are to be taken with the diaphragm preset exposuresystem, a desired diaphragm aperture value is set by the diaphragmsetting member and the braking means is unlatched from the sectoropening member to free the member from braking action. The unlatching ofthe braking means can be effected in operative relation to the diaphragmsetting operation by the diaphragm setting member. y

Upon depression of the shutter button, the sectors open lquickly to thepreset diaphragm aperture, permitting the photoreceptor to measure thereflected light from the film face in proportion to the diaphragmaperturejThe resulting output is integrated by the exposure time controlelectric circuit and when the integrated voltage has reached apredetermined voltage, the circuit actuates the sector closing member toinstantaneously close the sectors.

Thus photographs can be taken either with the programmingv exposuresystem or with the diaphragm preset exposure system as desired.

Other objects and features of this invention will become more apparentfrom the following description with reference to embodiment of thisinvention.

BRIEF DESCRIPTION OF THE DRAi/INGSl FIG. l is aview in vertical sectionschematically showing the construction of a camera to which the presentinvention is applied;

FIG. 2 is a front view showing the principal part of an electronicshutter embodying the present invention;

FIG. 3 is a front view showing the same as the sectors have been openedto the diaphragm aperture setting;

FIG. 4l is a front view showing the same as the sectors have been closedby a sector closing member;

FIGS. 5 and 6 are views illustrating the operation of the embodiment ofFIG. 2;

FIG. '7 is a front view showing the principal part of an electronicshutter in accordance with this invention by which photographs can betaken both on the programming exposure system and diaphragm presetexposure system, the shutter being set for programming exposure; f

FIG. 8 is a view showing the embodiment of FIG. .7 as the shutter is setfor diaphragm preset exposure; and

FIG. 9 is a view illustrating the operation of the embodiment of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. l, thereference numeral ll indicates a camera body and the numeral 2, anobjective lens. A photographic film 3 set in the camera body l isretained in position by a film pressing plate 4, with its reflectingface 3a directed toward the lens 3. A photocell 5 is retained by aholder 7 at a position suitable for receiving light reflected from thesurface 3a through a condenser lens 6.' The photocell receives the`diffused reflected light mainly from the upper half of the reflectingsurface 3a. The photocell 5 may preferablyvbe a cell such as aphotovoltaic cell which'is quick to respond 'to changes in the intensityof light. The holder 7 for the photocell is positioned at an upperportion of a dark case 8. A sector case 9 accommodates a sector openingand closing mechanism to be described later. Sectors l0 which areoperated by the sector opening and closing mechanism are positioned inthe light path Lof the lens 2. The interior of the dark case 8 islight-tight. Terminals 5a and 5b connect the photocell 5 to an electric.

circuit for controlling exposure time to be described later.

other stationary member. Normally, a suitable number of sectors l0 arearranged in overlapping relation to block the light passing through thelens. Each of the sectors l0 has a slot 10a receiving therein a pin 12aon a sector opening member l2 which is rotated reciprocally about theoptical axis of the lens by a mechanism to be described later. Theforward rotation of the opening member 12 causes the sectors to open todefine a set diaphragm aperture or a diaphragm aperture controlled bythe exposure time control circuit and the backward rotation of themember l2 closes the sectors to the original state shown in FIG. 2.. l

In the case of a lens shutter the sector opening member l2 is usually inthe form of an annular member as illustrated and is urged by a spring 13in a clockwise direction all the time, with a projection 12b on itsouter periphery in engagement with a latch portion 14a of a first latchlever 14 to tension the spring 13. When released from the first latchlever I4, the sector opening member l2 is driven in a clockwisedirection in the drawing for a forward rotation.

The first latch lever 14 pivoted to the sector case 9 or the like as atl5 is urged by a spring 16 in a counterclockwise direction in thedrawing and has at its tail end a lug 14h facing an electromagnet I7which is energized and de-energized by the exposure time controlelectric circuit. Upon energization, the electromagnet 17 attracts thelug Mb to pivotally move the latch lever M in a clockwise direction andto thereby unlatch the sector opening member l2, whereby the openingmember l2 is initiated into action. De-energization of theelectromagnetl7 permits the lever 14 to return to the original positionunder the action of the spring 16.

Pins 12e, 12d and 12e further project from the sector opening memberi12.

With the sectors 10 in closed position, the pin 12h` keeps a triggerswitch 13 of the exposure time control electric circuit closed. It opensthe trigger switch 18 to trigger the electric circuit upon the sectoropening member l2 being initiated into movement in the sector openingdirection.

The pin 12d is in contact with a driven portion 19a of asecond latchlever 19 which is pivoted to the sector case 9 as at 20 and biased by aspring 21. A lug l9b at the front end of the second latch lever 19,positioned close to a notch 22a in the periphery of a sector closing Asshown in FIG. 2, each of the sectors l0 is pivoted member 22, engages inthe notch 22a upon tensioning of the shutter to latch the sector closingmember 22.

The sector closing member 22 is pivoted to the sector case 9 or the likeas at 23 and urged by a spring 24'in a counterclockwise direction in thedrawing. Unillustrated means tensions the spring 24 in operativerelation to shutter cocking operation, whereupon the closing member 22is latched in the position illustrated in FIG. 2.

The sector closing member 22 is further formed in its periphery with aprojection 22b engageable with another lug 14C at the front end of thetirst latch lever 14, the arrangement being such that when the firstlatch lever 14 is pivotally moved with its lug 14h attracted to theelectromagnet 17 upon energization thereof, thelug 14C is brought intothe path of projection 22b to face the projection 22b.

When'the first latch lever 14 moves pivotally as described above uponthe energization of the electromagnet 17, permitting the sector openingmember 12 to start movement in the sector opening direction, the secondlatch lever 19 is moved in a counterclockwise direction to unlatch thesector closing member 22, whereupon the sector closing member 22 startsto rotate in a counterclockwise direction. Consequently, the projection22b comes into engagement with the lug 14n` of the first latch lever 14,whereby the closing member 22 is prevented from further counterclockwiserotation and comes to a halt. In other words, the sector closing member22 rotates counterclockwise a very small amount upon initiation ofmovement of the Vsector opening member 12. In order to allow for such aslight rotation, the lug 14C is spaced apart from the projection 22b bya small distance a in the state as illustrated in FIG. 2. The distance aserves to compensate for the time delay in the action of mechanicallyoperating members during the exposure time controlling operation of theexposure time control electric circuit for high speed operation of thesectors (i.e., for making an exposure of a short duration).

The sector closing member 22 further has a pin 22a` thereon in the pathof which there is disposed a driven arm 25a of a closing lever 25.

The closing lever 25, pivoted to the sector case 9 or the like as at 26,is urged in a clockwise direction by a spring 27 and has a drive arm 25bin contact with a pin 12e on the sector opening member l2. The sectorclosing member 22 is further formed with a notch 22d in opposingrelation to a stopper 28 which also serves as a retainer for holding thefixed end of the spring 24 so as to limit the angle of rotationaldisplacement of the closing member 22 to a definite range.

After the projection 22b comes into engagement with the lug 14C of thetirst latch lever 14 to temporarily stop the counterclockwise rotationof the sector closing member 22, the exposure time control electriccircuit detects that the film has received a suitable exposure by virtueof the opening of the sectors 10, whereupon the electromagnet 17 isde-energized. The de-energization of the magnet 17 permits the firstlatch lever 14 to immediately rotate in a counterclockwise directionunder the action of spring 16, releasing the projection 22b from the lug14e, with the result that the sector closing member 22 rotates in acounterclockwise direction under the action of the spring 24, causingthe projection 22C to push the driven arm 25a of the closing lever 25 torotate the lever 25 in a clockwise direction. As a result, the sectoropening member 12 is driven in a counterclockwise direction to close thesectors 10 since the pin 12e is pushed by the drive arm 25h of theclosing lever 25. This sector closing action takes place instantaneouslyupon the deenergization of the electromagnet 17. Thus, the springsincorporated in the above construction are such that under anyconditions, the sum of the force of the spring 24 acting on the sectorclosing member 22 and the force of the spring 27 acting on the closinglever 25 is sufficiently greater than the force of the spring 13 actingon the sector opening member 12.

The exposure time control electric circuit for controlling the openingand closing action of the sectors l0 comprises an integration circuit lincluding a circuit of a photocell 5 such as a photovoltaic cell, atransistor T and an integrating capacitor C connected in series andresistors Rl and R2 connected in parallel to the circuit and having aconnection therebetween coupled to the base of the transistor T tocontrol the voltage across the photocell 5 to a predetermined level; aswitching circuit SC for energizing the electromagnet 17 by loading thewinding of the electromagnet 17 with the voltage of the power source Eupon closing of the main switch SM and for de-energizing theelectromagnet 17 by discontinuing supply of current to the windingimmediately when the voltage across the capacitor C exceeds a givenlevel; and a trigger switch 18 which is opened upon the sector openingmember l2 being initiated into movement in the sector opening directionand is closed upon the completion of the backward movement of the sectoropening member 12, the main switch SM being adapted to close inoperative relation to the depression of the shutter button to open andclose the sectors l0. Thus the photo-receptor starts to measure thelight upon the initiation of opening of the sectors 10 to control theexposure of the sensitive coating of the tilm.

The means for presetting the diaphragm aperture of the objective lenscomprises a diaphragm ring 29 rotatably mounted on the lens barrel andbearing diaphragm aperture values f. The aperture value is set to a mark30 on a stationary member. The diaphragm ring 29 has an arm 29a having alug at its distal end which extends to the path of movement of an'arml2fextending from the outer periphery of the sector opening member 12.

More specifically, by manually rotating the diaphragm ring 29 to alignthe desired diaphragm aperture value f with the mark 30, the arm 29a isshifted to a set position corresponding to the diaphragm aperture valuef. The arm l2fof the sector opening member 1.2 which is initiated intorotation by the depression of the shutter button hits the arm 29a, whichtherefore prevents further rotation of the sector opening member l2 atthis position so as to permit the sectors l0 to define an aperturecorresponding to the diaphragm aperture setting. f

For diaphragm aperture value setting, the mark 30 may alternatively bepositioned on the diaphragm ring 29 for registry with the diaphragmaperture values f indicated on a stationary member on the lens barrel.Further in place of the foregoing construction wherein the diaphragmring 29 directly restricts the rotation of the sector opening member 12to give the preset diaphragm aperture, an intermediate member may beprovided which is operated by the diaphragm ring 29 to limit therotation of the sector opening member l2 and thereby obtain a presetdiaphragm aperture.

The means for braking the opening movement of the sectors l comprises,for instance, a delaying mechanism such as a slow governor and a brakingiever 36. The delaying mechanism is composed of a sector gear 3i, a gearsystem 32 meshing with the gear 3l, an escape wheel 33 in operativerelation to the gear system 32 and an anchor 34 to be reciprocallypivotally moved by the escape wheel 33. The braking lever 36 is pivotedto the sector case 9 as at 37 and has a driven arm 36a inv engagementwith a pin i2g on the sector opening member l2 and a drive arm 36b inengagement with a pin 31a on the sector gear 3i. The sector gear 31,pivoted to the sector case 9 or the like as at 3%, is urged by a spring39 in a counterclockwise direction in the drawing. The position of thebraking lever 36 is determined by a stopper 40.

When the diaphragm ring 29 is operated to set the diaphragm aperture,for example, at f lll and the shutter button is then depressed, theeiectromagnet E7 is energized to actuate the sector opening member l2 toeffect the aforementioned sector opening and closing action. Upon theinitiation of operation of the sector opening member ll2, the pin 12gthereon pushes the braking lever 36 pivotally in a counterclockwisedirection. The braking lever 36 in turn rotates the sector gear 3l in aclockwise direction in the drawing through a pin 31a thereon. However,since the sector gear 3H constitutes the known delaying mechanism alongwith the gear system 32, escape gear 33 and anchor 34, the delayingmechanism 3S acts on the sector opening member l2 through the brakinglever 36, so that the movement of the sector opening member l2 in thesector opening direction is braked to open the sectors l0 at a lowerspeed than when they are closed.

FIG. 3 shows a state wherein the sectors Ml have been completely openedwith the diaphragm aperture set atf il. In this state, the closingmember 22 is prevented from counterclockwise rotation by the first latchlever i4. De-energization of the electromagnet by the exposure timecontrol electric circuit immediately unlatches the sector closing member22 from the tirst latch lever 114i, permitting the member 22 to rotatecounterclockwise and close the sectors il@ as already described. Theparts are now in the state illustrated in FIG. 4i.

When the shutter is cocked after the sectors ttl have completely closedas seen in FIG. 13, the sector closing member 22 is driven in aclockwise direction, permit ting the lug i917 ofthe second latch lever29 to engage in the notch 22a to thereby retain the member 22 in itscocked position (see FIG. 2).

FIG. 5 diagrammatically shows the operation ofthe sectors il@ wherein itis assumed that the diaphragm aperture is set atf El. The diaphragmaperture valuefis plotted as ordinate vs. the exposure time T asabscissa.

The depression ofthe shutter button permits the sectoropening member l2to start to open while being braked bythe braking mechanism,progressively enlarging the diaphragm aperture from point a to point b.At time b', the diaphragm aperture for the settingf il is obtained,whereupon the sector opening action is completed. On the other hand, theexposure time control circuit starts to measure the light with itsphotoreceptor simultaneously with the initiation of opening of thesectors for charging the capacitor C of the integration circuit I. Uponthe lapse of a time suitable for giving a proper exposure to thesensitive coating of the film after the diaphragm aperture off lll isobtained, namely at point c where the voltage across the capacitor Cexceeds a predetermined level, the circuit deenergizes the electromagnett7 to initiate the sector closing member into operation. The sectors arecornpletely closed at point d. Thus, the amount of exposure during theexposure time of a to d corresponds to the area defined by lines ab, bc,cd and ad.

The foregoing description applies to the case wherein the diaphragmaperture setting is within the range of automatic exposure makingoperation for a highly bright subject. If the diaphragm aperture is set,for example, at f 2.8 and the subject has a relatively high brightnessoutside the range of automatic exposure, the shutter exhibits anoperation as illustrated in FIG. 6.

lt is assumed that when the sectors start to open upon the depression ofthe shutter button, the aperture gradually enlarges along the line ab",requiring a time b' for the diaphragm to open to the aperture ofj2.8..Attime b'", however, an overexposure will result, and in henceobjectionable. Accordingly, the exposure time control circuit, with itsphotoreceptor starting to measure the light upon the initiation ofexposure to start charging the intergrating capacitor C, de-energizesthe electromagnet upon detecting that the voltage across the capacitor Chas exceeded the predetermined level at point c" namely at time c"',with the result that the sectors start to close at point c" and completethe clos ing action at point d'. Thus, an amount of exposurecorresponding to the area defined by the lines ac", c"d', and ad' isgiven to the sensitive coating. In this way, a subject of a relativelyhigh brightness can be photographed with a proper exposure at whatevervalue the diaphragm aperture may be set within or outside the range ofautomatic exposure for highly bright subjects. Although the foregoingdescription and drawings cover the sector opening and closing mechanismwhich serves both as diaphragm means and shutter means, namely as ashutter acting as diaphragm blades and shutter blades, there may beprovided additional diaphragm blades for manually setting the diaphragmaperture. Unlike in the foregoing construction wherein,

even when the diaphragm aperture setting is within the range ofautomatic exposure for highly bright subjects, the sectors aretemporarily halted upon the sectors being opened to the preset diaphragmaperture, the sectors in this case will be switched into a closingaction upon completion of an opening action.

Further the first latch lever M can be engaged with or disengaged fromthe sector opening member i12 and the sector closing member 22 at suchpositions where the movement of the first latch lever M has beenaccelerated by gear means or the like so as to effect the engagement ordisengagement with a smaller force.

With reference to the foregoing embodiment, description will now begiven of an electronically controlled shutter adapted both forprogramming exposure and diaphragm preset exposure.

With reference to FIGS. 7 and 8, the diaphragm ring 29 is formed with acam face 29b at a suitable position in its inner periphery. The gears32a and 32b included in the gear system 32 of the braking mechanism aresupported on a pin la at the distal end of a changeover lever 4i pivotedto the sector case 9 or the like as at 412. The lever 4i is urged by aspring 433 in a clockwise direction in the drawing to bring its tail end41h into contact with the inner face of the diaphragm ring 29, thearrangement being such that when the mark 30 on the ring 29 is set to asymbol A, the tail end 41h engages in the cam face 29h to cause the gear32a to engage with the sector gear 3l and the gear 32b to engage withthe gear 32e as shown in FIG. 7, while when the diaphragm ring 29 isoperated to set the mark 30 to the desired aperture value f, the tailend 41h is pushed out of the cam face 29b into contact with the innerface of the diaphragm ring 29 so as to disengage the gear 32a from thegear 31 and the gear 32h from the gear 32C as seen in FIG. 8. A stopper44 defines the maximum aperture of the sectors when the mark 30 on thediaphragm ring 29 is set to the symbol A.

Thus the setting of the mark 30 to the symbol A causes the tail end 4lbof the changeover lever 4l to engage the cam face 29h as shown in FIG.7, effecting engagement between gears 31 and 32a and between gears 32hand 32e, so that when the shutter button is depressed to initiate thesector opening movement of the sector opening member 12, a braking forceacts on the member l2 so as to open the sectors at a lower speed thanwhen they are closed.

More specifically, the opening movement of the sectors l proceeds alongthe line ac as indicate at A in FIG. 9 to enlarge the aperture whilepermitting the exposure time control circuit to measure the reflectedlight incident on its photoreceptor. The moment the voltage across theintegrating capacitor exceeds a definite level, namely at point c" inFIG. 9, the circuit actuates the sector closing member 22 to close thesectors for completion of exposure. In this case, the diaphragm apertureis automatically controlled by the exposure time control circuit, makingit possible for the camera to take a photograph on the programmingexposure system wherein both exposure factors, i.e., exposure time anddiaphragm aperture are controlled automatically.

On the other hand, when a photograph is to be taken on a diaphragmpreset exposure system, the mark on the diaphragm ring 29 is set to thedesired diaphragm aperture value, for example, atf ll as shown in FIG.8, whereby the tail end 4lb of the changeover lever 4l is pushed out ofthe cam face 29b into contact with the inner face of the diaphragm ring29. The lever 41 is therefore turned about the pivot 42 in acounterclockwise direction in the drawing, freeing the gears 3l, 32a andgears 32h, 32C from meshing engagement respectively. The sector openingmember 12 is now free of a braking action.

Accordingly, the depression of the shutter button in the state of FIG. 8causes the sectors I0 to quickly open to the preset diaphragm aperturealong the line ab as indicated at B in FIG. 9 and expose the sensitivecoating. At point c which represents the moment when the voltage acrossthe integrating capacitor C exceeds a predetermined level, the sectorsclose quickly along the line cd. In this way a photograph is taken withthe diaphragm preset exposure system.

In this embodiment, the first latch lever 14 may also be engaged with ordisengaged from the sector opening member ll2 and sector closing member22 at positions where the movement of the lever has been accelerated bygear means or the like instead of direct engagement or disengagement.The engagement or disengagement will then be effected with a smallerforce.

Further in addition to the sectors 10, diaphragm blades may be providedexclusively for setting the diaphragm aperture. The diaphragm aperturemay then be set manually by the diaphragm blades. In this case, thesectors are so adapted as to close immediately when opened to themaximum aperture.

Although the braking mechanism is engaged with or disengaged from thesector opening member in operative relation to the manipulation of thediaphragm ring in the foregoing embodiment, the engagement ordisengagement may alternatively be effected by some other member.Further instead of meshing engagement or disengagement between the gears3l and 32a and between gears 32b and 32C, another gear, sector gear,anchor or the like may be adapted for engagement or disengagement forthis purpose. To this end it is likwise possible to utilize theengagement relation between the braking lever 36 and pin 12g.

Unlike in the embodiment in FIG. 2, the mark 30 in the above embodimentis provided on the diaphragm ring 29. However, the mark 30 can of coursebe positioned on a stationary member as in FIG. 2, with the diaphragmaperture values indicated on the diaphragm ring 29. Likewise, the markand value indications in FIG. 2 may be changed as seen in FIG. 7.

What is claimed is:

l. An electronically controlled shutter for a camera having a shutterincluding blades functioning as diaphragm and shutter blades comprising:

means including an opening member for driving said shutter blades in anopening direction,

braking means for braking the movement of said opening member,

diaphragm setting means having a stopping portion for intermediatelyhalting the opening movement of said opening member, said diaphragmsetting means being adjustable to permit said stopping portion to haltsaid opening member when said shutter blades have opened to a presetdiaphragm aperture,

photoreceptor means including a photocell for receiving and measuringthe reflected light from the surface of film in said camerasimultaneously with the start of said shutter blades opening to producean output in accordance with the intensity of the incident light,

an electromagnet, an exposure time control electric circuit meanscomprising an integration network including a capacitor for controllingsaid electromagnet in response to the integration of said output tothereby automatically control the exposure time, and

means including a closing member actuated by said electromagnet when thevoltage across said capacitor has reached a predetermined level so as todrive at least some of said shutter blades in a closing direction.

2. The electronically controlled shutter as set forth in claim l whereinsaid shutter opening blades and said shutter closing blades comprise thesame shutter blades.

3. The electronically controlled shutter as set forth in claim l whereinsaid diaphragm setting means has comprises means having a controlportion for controlling the engagement and disengagement between saidsector opening member and said braking means.

4. The electronically controlled shutter as set forth in claim 3including means for selectively setting the shutter in an exposureprogramming position and in a plul il rality of diaphragm presetexposure positions by adjusting said diaphragm setting means wherebywhen the shutter is set at the programming position said control portionfunctions to cause said braking means to brake the movement of saidopening member and when the shutter is set at a diaphragm presetexposure position said opening member is free of braking action topermit said shutter opening blades to progressively open to define thepreset diaphragm aperture, whereupon said blades come to a halt.

S. An electronically controlled shutter for a camera including shutterand diaphragm functioning blades comprising:

an opening member for driving at least some of said blades in an openingdirection,

braking means for braking the movement of said opening member,

a means including a manually operable changeover member for selectivelyengaging said braking means with or disengaging said braking means fromsaid opening member,

photoreceptor means including a photocell for receiving and measuringthe reflected light from the surface of film in said camerasimultaneously with the start of said shutter blades opening to producean output in accordance with the intensity of the incident light,

an electromagnet, an exposure time control electric circuit meanscomprising an integration network including a capacitor for controllingsaid electromagnet in response to the integration of said output tothereby automatically control exposure time, and

means including a sector closing member actuated by said electromagnetwhen the voltage across said capacitor has reached a predetermined levelso as to drive at least some of said shutter blades in a closingdirection.

6. The electronically controlled shutter as set .forth in claim whereinsaid opening shutter blades and said closing shutter blades comprise thesame shutter blades.

7. An electronically controlled shutter for a camera including shuttersectors comprising:

means including a sector opening member for driving at least some ofsaid sectorshin an opening direction,

means including a sector closing member for driving at least some ofsaid sectors in a closing direction,

braking means for braking the movement of said sector opening member soas to open said sectors at a lower speed than when said sectors areclosed,

photoreceptor means including a photocell for receiving and measuringthe reflected light from the surface of film in said camerasimultaneously with the start of opening of said sectors to produce anelectrical output in accordance with the intensity ofthe incident light,

an electromagnet, and

an exposure time control electric circuit means comprising anintegrating network including a capacitor for controlling saidelectromagnet in response to the integration of said output toautomatically control exposure time whereby when the voltage across saidcapacitor reaches a predetermined level said electromagnet causes thesector driving member to close said sectors.

8. The electronicallycontrolled shutter as set forth in claim 7 whereinsaid sectors serve as diaphragm'blades and shutter blades.

9. The electronically controlled shutter as set forth in claim includingdiaphragm setting means for manually presetting a diaphragm aperture forthe camera objective lens.

l0. The electronically controlled shutteras set forth in claim 9 whereinsaid diaphragm setting means includes means for stopping the openingmovement of said sectors when the diaphragm aperture of said sectorsreaches the preset diaphragm aperture value.

ll. The electronically controlled shutter as set forth in claim 7wherein said control circuit includes a switch, said electromagnet beingenergized by the closing of said switch and deenergized upon the voltageacross said capacitor exceeding said predetermined level, said sectoropening member being actuated by the energization of said electromagnetand said sector closing member being actuated by the de-energization ofsaid electromagnet.

l2. The electronically controlled shutter as set forth in claim lllincluding a latch member movable between advanced and retractedpositions and wherein said sector opening member is normally latched inits operation initiating position by said retracted latch member and isreleased for opening movement by said latch member being attracted andadvanced upon the energization of said electromagnet, and said sectorclosing member being latched in its cocked position by said sectoropening member and released from the latched position upon the initialadvance of said sector opening member for movement to a latched positionby said latch member after making a slight rotation, said sector closingmember instantaneously moving in the sector closing direction upon saidlatch member being retracted upon the de-energization of saidelectromagnet.

ll3. The electronically controlled shutter as set forth in claim l2wherein said sector opening member drives said sectors in their openingdirection while being braked by said braking means during its forwardmovement and is instantaneously returned to its operation initiatingposition by said sector closing member to close said sectors when saidsector closing member is unlatched from said latch member.

M. The electronically controlled shutter as claimed in claim 9 includingmeans for enabling and disabling said braking means so as to selectivelyalternatively brake said sector opening member or free the same from itsbraking action.

l5. The electronically controlled shutter as claimed in claim E4 whereinsaid braking means is engaged with or disengaged from s aid sectoropening member under the control of said manual diaphragm setting means.

M. The electronically controlled shutter as set forth in claim 7,wherein said photocell comprises a photorolatic cell.

17. The electronically controlled shutter as set forth in claim R6further comprising means including a constant current circuit (Rl, R2,C) for coupling the output of said photocell (5) to said integrationcircuit (C) as constant current.

113. An electronically controlled shutter for a photographic cameraincluding shutter exposure and closing blades comprising:

an opening means for driving said exposure blades in their openingdirection;

tric circuit means for controlling said electromagnet comprising anintegration circuit including a capacitor for integrating the output ofsaid photocell to thereby automatically control exposure time wherebywhen the voltage across said capacitor reaches a predetermined level,said electromagnet causes said closing means to close said closingblades. 19. The electronically controlled shutter as set forth in claimI8, further comprising means including a constant current circuit (R1,R2, C) for coupling the output of said photocell (5) to said integrationcircuit (C).

* 4S v ik vUNTTED STATES PATENT OFFICE CERTIFICATE OF CORRECTION3,757,655 Dated September ll, 1973 Inventor s) TATSUO KOBAYASHI It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as, shown below:

Patent No.

--30 Foreign Application Priority Data Japan Japan December 28,1970................a5128454 Signed and sealed this 23rd day of April197D..

(SEAL) Attest:

' C. MARSHALL DANN EDWARD I/I.FIETCHER,JR. Attesting; OfficerCommissioner of Patents UNITED STATES PATENT OFFICE CER'NFICATE 0FCORRECTIGN Patent No. 3 757,655 Dated September ll, 1973 Inventor(s)TATSUO KOBAYASHI It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as, shown below: v

--30 Foreign Application Priority Data Japan December 25, 1970..4S-125496 Jepee December 2s, 197o.*...`.....'.......45128454 Signed andsealed this 23rd day of April 197A.

(SEAL) Attest:

EDWARD M .FLETCHEPLJR C MARSHALL DANN Attesting; Officer' Commissionerof Patents

1. An electronically controlled shutter for a camera having a shutterincluding blades functioning as diaphragm and shutter blades comprising:means including an opening member for driving said shutter blades in anopening direction, braking means for braking the movement of saidopening member, diaphragm setting means having a stopping portion forintermediately halting the opening movement of said opening member, saiddiaphragm setting means being adjustable to permit said stopping portionto halt said opening member when said shutter blades have opened to apreset diaphragm aperture, photoreceptor means including a photocell forreceiving and measuring the reflected light from the surface of film insaid camera simultaneously with the start of said shutter blades openingto produce an output in accordance with the intensity of the incidentlight, an electromagnet, an exposure time control electric circuit meanscomprising an integration network including a capacitor for controllingsaid electromagnet in response to the integration of said output tothereby automatically control the exposure time, and means including aclosing member actuated by said electromagnet when the voltage acrosssaid capacitor has reached a predetermined level so as to drive at leastsome of said shutter blades in a closing direction.
 2. Theelectronically controlled shutter as set forth in claim 1 wherein saidshutter opening blades and said shutter closing blades comprise the sameshutter blades.
 3. The electronically controlled shutter as set forth inclaim 1 wherein said diaphragm setting means has comprises means havinga control portion for controlling the engagement and disengagementbetween said sector opening member and said braking means.
 4. Theelectronically controlled shutter as set forth in claim 3 includingmeans for selectively setting the shutter in an exposuRe programmingposition and in a plurality of diaphragm preset exposure positions byadjusting said diaphragm setting means whereby when the shutter is setat the programming position said control portion functions to cause saidbraking means to brake the movement of said opening member and when theshutter is set at a diaphragm preset exposure position said openingmember is free of braking action to permit said shutter opening bladesto progressively open to define the preset diaphragm aperture, whereuponsaid blades come to a halt.
 5. An electronically controlled shutter fora camera including shutter and diaphragm functioning blades comprising:an opening member for driving at least some of said blades in an openingdirection, braking means for braking the movement of said openingmember, a means including a manually operable changeover member forselectively engaging said braking means with or disengaging said brakingmeans from said opening member, photoreceptor means including aphotocell for receiving and measuring the reflected light from thesurface of film in said camera simultaneously with the start of saidshutter blades opening to produce an output in accordance with theintensity of the incident light, an electromagnet, an exposure timecontrol electric circuit means comprising an integration networkincluding a capacitor for controlling said electromagnet in response tothe integration of said output to thereby automatically control exposuretime, and means including a sector closing member actuated by saidelectromagnet when the voltage across said capacitor has reached apredetermined level so as to drive at least some of said shutter bladesin a closing direction.
 6. The electronically controlled shutter as setforth in claim 5 wherein said opening shutter blades and said closingshutter blades comprise the same shutter blades.
 7. An electronicallycontrolled shutter for a camera including shutter sectors comprising:means including a sector opening member for driving at least some ofsaid sectors in an opening direction, means including a sector closingmember for driving at least some of said sectors in a closing direction,braking means for braking the movement of said sector opening member soas to open said sectors at a lower speed than when said sectors areclosed, photoreceptor means including a photocell for receiving andmeasuring the reflected light from the surface of film in said camerasimultaneously with the start of opening of said sectors to produce anelectrical output in accordance with the intensity of the incidentlight, an electromagnet, and an exposure time control electric circuitmeans comprising an integrating network including a capacitor forcontrolling said electromagnet in response to the integration of saidoutput to automatically control exposure time whereby when the voltageacross said capacitor reaches a predetermined level said electromagnetcauses the sector driving member to close said sectors.
 8. Theelectronically controlled shutter as set forth in claim 7 wherein saidsectors serve as diaphragm blades and shutter blades.
 9. Theelectronically controlled shutter as set forth in claim 8 includingdiaphragm setting means for manually presetting a diaphragm aperture forthe camera objective lens.
 10. The electronically controlled shutter asset forth in claim 9 wherein said diaphragm setting means includes meansfor stopping the opening movement of said sectors when the diaphragmaperture of said sectors reaches the preset diaphragm aperture value.11. The electronically controlled shutter as set forth in claim 7wherein said control circuit includes a switch, said electromagnet beingenergized by the closing of said switch and deenergized upon the voltageacross said capacitor exceeding said predetermined level, said sectoropening member being actuated by the energization of said electromagnetand said sector closing member being acTuated by the de-energization ofsaid electromagnet.
 12. The electronically controlled shutter as setforth in claim 11 including a latch member movable between advanced andretracted positions and wherein said sector opening member is normallylatched in its operation initiating position by said retracted latchmember and is released for opening movement by said latch member beingattracted and advanced upon the energization of said electromagnet, andsaid sector closing member being latched in its cocked position by saidsector opening member and released from the latched position upon theinitial advance of said sector opening member for movement to a latchedposition by said latch member after making a slight rotation, saidsector closing member instantaneously moving in the sector closingdirection upon said latch member being retracted upon thede-energization of said electromagnet.
 13. The electronically controlledshutter as set forth in claim 12 wherein said sector opening memberdrives said sectors in their opening direction while being braked bysaid braking means during its forward movement and is instantaneouslyreturned to its operation initiating position by said sector closingmember to close said sectors when said sector closing member isunlatched from said latch member.
 14. The electronically controlledshutter as claimed in claim 9 including means for enabling and disablingsaid braking means so as to selectively alternatively brake said sectoropening member or free the same from its braking action.
 15. Theelectronically controlled shutter as claimed in claim 14 wherein saidbraking means is engaged with or disengaged from said sector openingmember under the control of said manual diaphragm setting means.
 16. Theelectronically controlled shutter as set forth in claim 7, wherein saidphotocell comprises a photovoltaic cell.
 17. The electronicallycontrolled shutter as set forth in claim 16 further comprising meansincluding a constant current circuit (R1, R2, C) for coupling the outputof said photocell (5) to said integration circuit (C) as constantcurrent.
 18. An electronically controlled shutter for a photographiccamera including shutter exposure and closing blades comprising: anopening means for driving said exposure blades in their openingdirection; a closing means for driving said closing blades in theirclosing direction; governor means for governing the movement of saidopening means so as to open said exposure blades at a lower speed thanthe closing speed of said closing blades; means including aphotoreceptor including a photocell for receiving and measuring thereflected light from the surface of film in said camera simultaneouslywith the start of opening of said exposure blades to produce an outputin accordance with the intensity of the incident light; anelectromagnet, and an exposure time control electric circuit means forcontrolling said electromagnet comprising an integration circuitincluding a capacitor for integrating the output of said photocell tothereby automatically control exposure time whereby when the voltageacross said capacitor reaches a predetermined level, said electromagnetcauses said closing means to close said closing blades.
 19. Theelectronically controlled shutter as set forth in claim 18, furthercomprising means including a constant current circuit (R1, R2, C) forcoupling the output of said photocell (5) to said integration circuit(C).